Pickling tank



J. R. BRQQKS PICKLING TANK Filed June 3, 1929 Wam/M Patented July 4, 1933 UNITED earner JOSEPH R. BROOKS, 0F CHSCAGO, LLNOIS, ASSSGNOR GF ONE-HALF T0 XVILBUR R. POUNDER, OF CHICAGO, LLINGXS Application filed June 3, 1929.

This invention relates to the construction of pickling tanks, more particularly to the method of preventing the acid in those tanks from attacking the metallic parts of the tank.

In the manufacture of metallic parts that are to be plated, it is necessary to immerse the parts in a solution of strong acid to remove the grease that has collected on the surfaces of the parts during the process of fabrication so that those surfaces will be clean and in condition for plating. lhis process is ordinarily7 called pickling,

Tanks for holding the pickling bath are usually approximately l() feet long. lr feet 5 wide and 3 or 4 feet deep, and it has been found that a tank constructed of wood, preferably cypress, best resists the action of the acid used in the pickling bath.

These tanks have heretofore been constructed by piling timbers of cypress .voiid one upon the other with a narrow strip rabbeted into the joining surfaces of the timbers to form tight joints between the surfaces. The assembly so made has been held together by bolts running through the timbers on the opposite sides of this narrow seal.- ing strip, these bolts being equipped with nuts and Washers which are dra in tight to Q firmly hold the assembly together. These r semblies, made in co 1rect lengths, form the sides, ends and bottoms of the tanks, lvhic-h are held together by suitable metal bolts on the outside of the tank.

It has been found that even though the cypress wood is not attacked by the acid of the pickling' bath, that acid penetrates into the wood and quickly attacks the metal bolts used to hold the assemblies together. The life of these bolts has been extremely short, and frequent renewals of the bolts have been necessary. Those bolts employed to hold the tank together, that is, the bolts external of the assemblies, are not attacked as rapidly asthose embedded in the wooden assemblies, and although some rusting; of these binding' bolts occurs, it is not as serious as the rusting' of the bolts imbedded in the sides, ends and bottoms of the tanks.

The principal object of my present inven- FCKLl'NG TANK Serial No. 367,959.

tion resides in the provision of a method of protecting the bolts which hold vthe assemblies forming; the sides, ends and bottoms of the tanks together a method which prevents the acidv that seep. lto the wooden members of the tank from attacking' the metal in the bolts that hold the mei'nbers together.

In the preferred embodiment of my invention l encase tl ie bolt in a seamless tubingl of lead or other suitable acid resisting,` material. l counterbore the top and bottom members ot the assembly, and extend the end of the bolt and the end of the sleeving` into that counterbore. The bolt heads or nuts and washers, employed to lock the assembly together, are disposed in this counter-bore, which is then lille-d with an acid resisting' material that tightly seals against the end of the sleevinp; that projects into the counterbore. Preferably, this sealing material is lead which,

where molten is poured into the counterbore and made to seal with the lead sleeving on the bolts so as to completely encase the bolts, nuts and washers in a coating` of lead, which coating resists the acid and Yprevents corrosion of the bolts. The ends of the bolts, whi e they project into the counterbores, fall short of the surface of the wooden members, so that when the counterbore is filled with lead or other suitable acid resisting material, the outer surface of this material is flush with the outer surface of the mcinbers.

Although l have found that it not necessary to protect the bolts employed to hold the sides and bottom of the tank together by this process, it will-be seen that these bolts may also be encased in lead sleeving and heads disposed in counterbores that are filled with an acid resisting material, if it 'is desired to do so.

To acquaint those skilled in the art with the preferred embodiment of my invention, l have illustrated it in the accompanying drawing, in which Figure l. is a plan view of a portion of a tank made in accordance with the teachings of my invention Figure 2 is a cross sectional view of Figure. l, taken along;l the line 2 2 looking inthe direction of the arrows;

Figure 3 is a cross sectional view of Figure 2 taken along the line 3-3 looking in the direction of the arrows; and

Figure 4 is a cross sectional view showing a modified form of my invention.

Referring to the drawing in more detail, it Will be seen in Figure 2 that the end s-ection of the tank is made up of wooden timbers 1, 2, 3 and 4 which are stacked one upo-n the other with the sealing strip members 5 set in suit-able grooves in these timbers, to form a seal between them. In the usual construction of a tank of this kind, the timbers 1, 2, 3 and 4 are made of cypress wood, it having been found that this wood best resists action of the acid employed in the pickling process. Obviously, however, any other suitable form of acid resisting material may be used instead of cypress wood within the teachings'of my invention. rFliese timbers, 1 to 4, inclusive, are of sufficient lengths to form the end section of the tank, and when stacked together are of sullieient height to meet the depth requirements of the tank. Usually each timber is approximately 8 inches square, and has a length depending upon its position in the tank.

The sealing strips 5 are smaller cypress strips, usually approximately three quarters of an inch thick and an inch and a half wide, being set half of their width in each of the two timbers with which they are in engagement.

To hold this assembly of timbers together, bolts 30, 31, 32, 33 and 34 are disposed in bolt holes in staggered relation with respect to the sealing strips 5. That is, bolts 30. 32 and 34 are disposed on one side of the center line of the assembly, and are on one side of the sealing strips 5, while the bolts 31 and 33 are disposed on the opposite side of these sealing strips.

These bolts 8 are encased in a seamless sleeve 9 which is preferably made by casting lead on the bolts. The sleeves are fixed against movement with respect to the bolts. The bolts are disposed in suitable bolt holes which are drilled large enough to permit the lead sleeves to freely slide therethrough.

At the opposite ends of each of the bolt holes I have provided counterbores, such as 30 and 35, into which the end of the bolt placed in the hole, and the sleeve surrounding it, both project.

The end of the sleeve that projects into the counterbore is scraped bright. and talloW applied to this bright surface 14. The washer 11 is slipped over the end of the bolt and made to bear against the end of the sleeving 9, being held thereon by the nut 10 threaded onto the bolt.

When both ends of the bolts are so equipped with nuts and washers, and the nut drawn down to the proper tension, moltenV lead is poured into the counterbore to form l chunk of lead or seal 12, which completely encases the washer, nut and end of the bolt. The tallow rubbed on the bright surface 14 of the sleeve 9 fluxes this molten lead and causes it to seal perfectly with the sleeve 9 along the line 14, so that the end of the bolt is completely encased and protected by the lead seal 12.

Inasmueh as the wood expands somewhat after it has become soaked with the water and acid in the pickling bath, it is not necessary to apply a great deal of tension to the bolt 8 when the tank is being manufactured. I have found that when the bolt 31, shown in Figure 1, is inserted into the bolt hole, and bolts 30 and 32 are drawn down tight, the nut on the bolt 31 can be drawn down linger tight and then sealed into place. The tension on bolts 3() and 32 bring the members, 1 to 4, inclusive, sufficiently tight together that the linger tight adjustment of the bolt 31 is sufficient, so as to hold these members together and to form a liquid tight joint between adjacent ones of the members. Similarly, the finger tight adjustment is made on each of the other bolts, which are in turn sealed in by molten lead poured in the counterbore around their respective heads. If desired, the timbers 1 5, inclusive, may be drawn together by clamps or other preferred means, and the bolts 30-34 all tightened and sealed in one operation.

In the preferred embodiment of my invention the acid resisting sleeve 9 is fitted tightly on the bolt 8, but, obviously, if desired, the sleeve may be loosely fitted on the bolts, since in the assembled structure a tight seal is maintained between the sleeve and the seals over the end of the bolts, and there is no possibility of acid getting inside of the sleeve and attacking the bolt. lVith the sleeve tightly sealed on the bolt, the assembly may be more easily handled, since the sleeve and bolt are treated as one piece.

In Figure 4 I show a modified form of my invention in which the bolt 20 is encased in the acid resisting sleeve 21, as before, with the end of the bolt and sleeve projected into the counterbore 27. In this modification of the invention the counterbore 27 is of somewhat larger diameter than the counterbores used heretofore, and the end of the sleeve 21 is flanged over at 22 against the bottom surface of the counterbore. The washer 23 bears against this flanged end of the sleeve 21, and the nut 24 bears against the washer. The flange 22 is larger than the washer 23, and the surface 25 of the flange which projects beyond the washer is cleaned and coated with tallow, as before, so that when the molten lead 26 is poured into the counterbore it unites with the flange 22 of the sleeve 21 and forms a seal outside of the bearing surface of the washer on the flange. The nuts, washers and bolts are thereby tightly sealed in place against the entrance of' acid from the pickling bath.

This modification has the advantage that more tension can be placed on the bolt 2O by tightening the nut 24, for the reason that the Washer 23 squeeZes the soft flange 22 of the sleeve 2l against the bottom of the counterbore.

rlhis tension does not cause buckling of the sleeving, and therefore does not impair' the seal, as would result if an extremely high tension Were placed on the sleeve end prior to the pouring of the molten seal. This modification of the invention has the disadvantage of forming the flange 22 on the end of the sleeve, which disadvantage, in some instances, more than offsets the advantage gained by using the modification and renders its use less desirable. The modifica tion shown in Figure l is particularly adaptable for use in tanks made of material which does not expand appreciably when soaked With acid and Water, the members of which tank must be drawn more tightly together than the members of a Wooden tank need to be.

In ass-embling the tank from the side ends and bottom members so constructed, auxiliary sealing strips 5 are fitted into grooves rabbeted in the ends and side of these members, so that the assembled tank is sealed acid tight without the use of caulking materials. Bolts, such as 7, are employed to hold the component parts of the tank together, and, if desired, these bolts and their associated nuts and Washers may be protected in the same manner as the bolts which hold the components together.

Tanks made in accordance with the teachings of my invention are solidly built, are

free from both projecting and recessed bolt heads, and are therefore both long lived and of practical simplicity. The counterbores are filled iiush with the surfaces in Which they are located, .so that these surfaces are smooth and contain nothing that is apt to catch and tear the clothing of the Workmen employed in dipping objects in the tanks.

It is not necessary to use a lead sleeve and a lea-d seal in my invention7 as rubber., sarco asphaltum or any other acid resisting material may be employed With satisfactory results. A lead sleeve around an iron or steel bolt, together' with a lead seal over the iron or steel nuts and Washers, constitutes a combination having high tensile strength, and since the lead is non-porous and noncorrosive in acid, the combination is long lived. Furthermore, this combination has the advantage orl being made of relatively cheap material, and its use in the preferred embodiment of the invention is therefore less costly than bolts and Washers made of socalled acid proof metals.

lVhile l have chosen to show a preferred embodiment oi my invention, I have done so by Way of example only and am not to be limited thereby, as there are many modifications and adaptations Which can be made by one skilled in the art, Without departing from the scope of' the invention.

Having thus complied with the statutes and shown and described a pref-erred embodiment of my invention, what I consider new and desire to have protected by Letters Patent is pointed out in the appended claims.

lVhat is claimed is l. An acid resistant tank comprising a plurality of Wooden members laid one upon the other, grooves in said members, Wooden strips fitted in said grooves, and joining adjacent ones of said members together, there being bolt holes drilled through said members independently of said grooves and counterbored at their ends, bolts extending through said holes, lead sleeves on said bolts, said sleeves projecting into said counterbores, nuts and Washers disposed in said counterbi'ires and threaded upon said bolts and against the ends of said sleeves, and lead seals disposed in said couuterbores around said nuts and Washers and fused to the ends of said sleeves to thereby completely encase said bolts, nuts, and Washers in lead.

2. In combination with a Wooden body' having a bolt hole extending therethrough and counterbored at its ends, a bolt extending through said hole and into said counterbores, an acid resistant metal sleeve cast upon said bol* and extending into said counterbores and fiared radially outwardly i'against the bottoms of the counterboresi, washers disposed over said bolt and against the flared portions of said sleeve, said washers being oli substantially smaller diameter than the flared portions of said sleeve, nuts threaded on said bolt and against said Washers, and a mass of said acid resistant metal encasing the bolt ends, the nuts` and the Washers, and fused to the part of said sleeve extending beyond said Washers to seal the sleeve.

ln witness whereof, l hereunto subscribe my name this 25 day of May, 1929.

JOS. R. BROOKS. 

